Portable heater



T. F. SPACKMAN July 2, 1946.

PORTABLE HEATER 3 Sheets-Sheet l Filed Feb. 22, 1943 Jur 2, 1946 T. F. sPAcKMAN PORTABLE HEATER Filed Feb. 22, 1945 July 2, 1 946.

T. F. SPACKM AN PORTABLE HEATER Filed Feb. 22, 1943 3 Sheets-Sheet 3 wmrlm CrC I MUM HI (Iliarrrag Zj 5'.

Patented July 2, 1946 FFICE.

PORTABLE HEATER Chicago, Ill., assignor to Thomas F. Spackman, Stewart-Warner Cor por corporation of Virginia My invention relates to a carriage for supporting a heating unit for providing ready portability to the unit and also for port at the time the unit is being operated as a heater.

The object of my invention is theprovision of means for very quickly and reliably changing the heater carriage from its rigid runner supports to its wheel supports, and vice versa.

Portable heaters for airports, particularly for airplanes in combat use, must be changed from one location to another without delay. Heaters of the type for which my support is intended weigh in the neighborhood of 300 pounds, and in order that they may be moved by one operator on snow or through mud or on dry ground or concrete runways, it is desirable that they be provided with broad based runners for use under one condition of movement as well as with wheels for use under the other condition of movement, the runners forming a base when the heater is in operation for warming airplane motors or cabins.

In accordance with my invention, the wheels are supported at the ends of swinging arms pivoted on the carriage frame and adapted to swing like a pendulum past a dead center in one direction against a Spring-stop which maintains the wheel treads below the base of the runners, and in the other direction against a stop which maintains the wheel treads above the base of the runners. To move the wheels from one position to the other, it is only necessary to lift the end of the carriage to such a height that the wheels in their lowermost position will miss the ground, then release a catch permitting the arms and wheels to swing about their pivotal support until they have passed dead center, and then release the lifted end of the carriage, whereupon the arms and wheels will be moved to their alternate positions in which they are located until again released. g I

My invention is illustrated in the accompanying three sheets of drawings, in which:

Fig. 1 is an elevation of the carriage and its supported heater mechanism with one wheel omitted and showing the remaining wheel in position for supporting one end of the carriage;

Fig, 2 is an elevation of a fragmentary part of the cariage and itssupported heater mechanism in which one wheel is omitted and the remaining wheel is in its lifted position which it assumes when the carriage rests on its runners;

Fig. 3 isa fragmentary section taken on the line 35 30153134;

providing a solid supation, Chicago, 111., a

Application February 22, 1943, Serial No. 476,727 8 Claims. (01, 2809) i 2 Fig. 4 is a fragmentary section taken on the line 4-4 of Fig. 1;

Fig.v 5 is a fragmentary section taken on the 'line ,5-5 of Fig. 4;

Fig. 6 is a fragmentary section taken on the line 6-4: of Fig. 4, illustrating the connection of the torsion shaftwith the stub shaft for the wheelcarrying swinging arms;

Fig. 7 is a fragmentary section taken on the line 1.'! of Fig. 1;.and

Fig. 8 is a fragmentary 88 of. Fig. 1. v

Referring more particularly to Fig. 1, the car riage comprises a frame composed of upper and lower lineal tubular members l0 and Il located at each side of the carriage. The members I 0 and H are rigidly attached to one another by section taken on the line vertical tubular members 12 .and 13, preferably 9 Bee. is

welded to the lineal members i0 and H. The forward ends of the lineal members In and II are bent at right angles and extend across the front of the carriage where they are attached together by vertical members I4 andjoin with the members l0 and II at the opposite side of the carriage. 'A tubular handle attachment member [6 is welded to the member II at l1 and to the rear end of the member ticaltubular member I ID at, Hi, there being a ver- 9 extending between the rear end of the lineal member H and a position 26 on a horizontal portion of the handle attachment member. IS. A handle 2| formed of tubing sufficiently larger than the handle attachment member l6 to. slip snugly over it has welded thereto a brace 23 attached to the vertical member I9 and the horizontal handle attachment member I6 by suitable means such asbolts 25 and 26. By removin these bolts the handle and the brace member 23 may be slipped rearwardly and thus 1 removed to decrease the size of the'carriage forv shipping purposes.

A runner 36, slightly curved upwardly at one end and curved upwardly into a rocker at the other end, is attached to the frame members by means of a plate 3| by bolts 33 and 34' which extend through a Z-bar 35 which is Welded to the lower frame member! I as illustrated more clearly in Figs. 7 and 8.

The wheel-carrying swinging arm 3'! has a channel-shaped cross section for, rigidity and is pivoted at38 to the plate 3|, there being a stub shaft 40 suitably attached, preferably by welding,- at the pivot locationof the swinging arm 31. Se,- curely riveted'to the inner face of the swinging arm 31 is a hardened steel locking disc 43 whose concentric about the ax'is'upon which the j from the hub 56.

are of such size as riage strike obstacles on the roadway.

' for the swinging arm arm 31 is mounted, except that it is provided with two rectangular notches 44 and 45, the

the runner when the swingingarm is rotated to the counter-clockwise position shown in Fig. 2 and in dotted lines in Fig. 1. A detent 50 which fits rather closely within either of the notches 44 and 45 in the locking disc 43, is pivoted on the bolt 34 which assists in securing the plate 3! to the Z-bar carried by the lower frame member H. A lever 52 is attached to the for swinging the detent in a clockwise direction in Fig. 1 about the pivot bolt 34 by lifting the forward end of the lever 52 against the tension of the spring 54. The shaft has bearing rings which journal it for rotation within a hub 56 rigidly secured to the plate 3|, A c-spring 51 is snapped into a groove in the shaft 40 to form an abutment against the withdrawal of the shaft 49 Two housings and BI containing springs 62 and 83 are attached to the outside of the plate 3|, the housings being provided with slots '64 and (55 shown in Figs."7 and 8 forreoelving the upper edge of' the swinging arm 31. The slots 64 and '65 somewhat snugly, and since the slots are at different levels, they'serve to steady the swinging arm 37 and prevent its wabbling under the stresses applied to it when the wheels of the cIt tlr; e springsjEiZ and '63 are not of sufficient strength to support the load of thevehicle, but act merely to decrease the shock when the carriage is dropped onto the wheels at .the time it is being shifted from its runner support to its wheel sup-port.

The side of the carriage not shown in the drawthe lower dead center.

detent member 50 to engagethe swinging arm 31 I ings is provided with a swinging arm and wheel like those shown and described, except that the locking mechanism is omitted. The stub shaft llb't shown 'lis provided with a squared .end like '61 fitting into the square ended tubular shaft 68. Thus the two arms and their carried wheels are required to swing together, The side of the carriage not shown is provided with springs like 62 slotted housings 6B and 6| which perform the sain'effunction as those illustrated. v r The operation of the preferred embodiment of my invention just described is as follows: Assuming the carriage to be resting on the ground on its two runners 3i), with the arms 31 holding the and s3 and with wheels 41 in' raised position as shown in Fig. 2,

and that the attendant desires to move the carriage' to a remote position by rolling it onits Wheels rather than by sliding it on the ruimers, he will grasp the cross bar forming a part of the frame at the front end of the carriage at the left in Fig. l and lift that end'until the distance of the pivot point 38 for the arms3'l above the ground is greater than the diameter of the wheel 41. In lifting one end of the carriage, the rocker ends of the runners roll on the ground and the center of mass of the air heater and its associated tanks and other parts comes into a position approaching a lateral plane extending vertically from the point of contact with the ground.

iii)

When the carriage is in this position, only a very slight effort is needed for steadying the carriage.

The attendant now removes one hand from the cross bar of thefrarne by which one end of the carriage has been raised, and with that hand lifts the free end of the leveriz, thus swlngi'ngthe detenttil about its my ta l and releaslngthe '4 notched disc 43 and its attached swinging arm 31. The swinging arms carrying the wheels 41 now drop by gravity, and since the shafts 4i] and the hubs 56 are freely' rotatable in the plates 31 of the frame, the wheels and swinging arms swing downwardly and forwardly like a pendulum past As this happens, the attehdant lowers the end of the carriage, throwing its weight upon the wheels which now become locked in their running position as shown in Fig. 1 by reason of the detent 5i) snapping into the notch 44 in the hardened disc 43 through the influence of the spring 54. Since the two shafts '40 on opposite sides of the vehicle are attached together by means of their squared ends 61 and the hollow interconnecting shaft 98, the swinging arms and wheels on each side of the carriage move together from one position to the other, When the attendant desires to place the weight of the carriage back upon its runners, he again lifts the. end of the carriage as before, lifts the lever 52 as before, and again drops the end of the carriage after the wheels have swung downwardly and rearwardly past the lower dead center. This causes the wheels and their supporting swing ing arms to swing in a counter-clockwise direction in Fig. 1 with sufficient momentum to carry them a short distance above the ground level, where upon th'edetent 50 again drops into the notch 5 so located as to hold the wheels 41' slightly above the ground asshown in Fig. 2. r t I In the operations as above described, the lever 52 is released by the operator as soon as the detent "5i! is disengaged from the notch 44 or '45. The end of the detent thereafter engages the circular face of the member 43 until the Other ndth iS brought into registering position for engagement by the detent automatically.

When the wheels are in the position shown in solid lines in Fig, '1, the attendant rolls the vehicle like a two-wheeled push-cart, and when the wheels are in the position shown in dotted lines in the attendant pulls or pushes the earr-i'age as asle'd, 7

While have shown and described a preferred embodiment of 'my invention, it will be readily understood by those skilled in the art that varia time may be made in the construction disclosed without departing from the basic features of my invention, 1 therefore do not wish to be limited to the'precise construction disclosed, but to inch'lde within the scope of my invention all such modifications and variations which will readily suggest themselves,

Having thus described my invention, what I claim as 'newan-d useful and desire to secure by letters Patent of the-United States is:

i. In a carriage, a pair of runners upwardly turned at the ends, a frame structure carried by the runners, apair 'of swinging arms each pivoted at one end to opposite sides of the frame struc tu're, a pair of wheels one mounted upon the swingingend of each of the swinging arms, a shaft extending across the carriage interconnecting the swinging arms, and means for looking the swinging arms releasably in either of "two positions on opposite sides of a dead center position lower than either of said two positions, one position of the swinging arms being such as to hold the wheel treads above the lower surface of the runners and the other position of the swinging arms being such as to hold the wheel treads below the lower'sur'face of the runners, the ar V wish of said two'po'si tions and with the carriage tipped upwardly to subtantially vertical position above the upwardly turned ends of the runners the arms are adapted to swing past the dead center position so as to be brought to the other of said two positions and to be locked releasably in such other position.

2. In a carriage, a pair of runners upwardly turned at one end, a frame structure carried by the runners, a, pair of swinging arms each pivoted at-one end to opposite sides of the frame structure remote from thecurved up ends of the runners, a pair of wheels, one mounted near the swinging end of each of said swinging arms, means interconnecting said arms to cause them to swing together, and means for locking the swinging .arms in a position on one side of the dead center position with the wheel treads extending below the bearing surfaces of the runners or alternatively in a position on the other side of the dead center position with the wheel treads raised above the bearing surfaces of the runners, said locking means comprising a notched member attached to move with said swinging arms and having a face portion concentric with the axis about which said arms swing, and detent means adapted by engagement with a notch in said member to hold said member in either of said two positions and adapted to be held out of locking engagement with said notched member at all intermediate positions of the arms between said first named two positions, the arrangement being such that when the carriage is tipped upwardly into substantially vertical position above the upwardly turned ends of the runners with the arms in either of said two positions the arms when released are adapted to swing past the dead center position so that the weight of the carriage on the wheels when the carriage is brought back to normal position causes the arms to be moved into the other of said two positions so as to ,be releasably locked in such other positionby said locking means.

3. In a carriage, a pair of runners upwardly turned at one end, a frame structure carried by the runners, a pair of swinging arms each pivoted at one end to opposite sides of the frame structure, a pair of wheels one mounted near the swinging end of each of the swinging arms, means interconnecting the swinging arms to cause them to move to the same angles in parallel planes, a plate attached to one of the arms having two notches therein, a detent adapted to engage each of the notches in said plate, one notch of said plate being located so as to register with the detent when the swinging arm is moved to-' ward the upwardly turned end of the runner, the other notch in said plate being located in such a position as to register with the detent when the swinging arm is moved to a position away from the upwardly turned end of said runners, one of said notches being positioned to hold the tread of the wheel above the lower surface of the runner when the detent registers with the notch, the other of said notches being positioned to hold the tread of the wheel below the lower surface of the runner when that notch registers with the detent, and means to withdraw the detent from engage: ment with either notch to permit the arms and wheels to swing like a, pendulum from either position of registration to the other position of registration when the carriage is tilted on the upwardly turned ends of the runners sufilciently to permit the wheel treads to clear the ground as the pivoted arms and wheels swing from one position to the other.

face of the runners and the other locking position of the swinging arms being such as to hold the wheel treads below the lower surface of the runners, a spring against which one of said swinging arms abuts when the arm is locked with the wheel tread below the lower surface of the runners, the spring being compressed by the weight of the carriage, and its load upon the wheels, and means to release the arm from said locked position when one end of the carriage is lifted whereby reaction of the spring assists gravity to cause the swinging arms and wheels carried thereby to swing like a pendulum past the lower dead center.

5. In a carriage, a pair of runners, a frame structure carried by the runners, a pair of swinging arms each pivoted at one end to one of the opposite sides of the frame, a pair of wheels one mounted near the swinging end of each of the swinging arms, the swinging arms being adapted to swing from a position substantially parallel with the base of the runners passed the lower dead center to a position at a substantial angle above the plane of the runners, a pair of abutments on one of said swinging arms, one located substantially the same distance from the pivot for said swinging arm as the axis of the wheel carried by the swinging arm, the other of said abutments being located at a greater distance from the pivotal support for said swinging arm, said abutments being located in diiferent horizontal planes, one abutment being on substantially the horizontal line of the axis of the wheel when the weight of the carriage is on the wheel and the second abutment being considerably above the first abutment, and a pair of stops having slots into which said abutments snugly fit.

6. In a carriage, a pair of runners, a frame structure carried by the runners, a pair of swinging arms each pivoted at one end to one of the opposite sides of the frame, a pair of wheels one mounted near the swinging end of each of the swinging arms, the swinging arms being adapted to swing from a position substantially parallel with the base of the runners passed the lower dead center to a position at a substantial angle above the plane of the runners, a pair of abutments on one of said swing ng arms, one located substantially the same distance from thepivot for said swinging arm as the axis of the wheel carried by the swinging arm, the other of said abutments being located at a greater distance from the pivotal support for said swinging arm, said abutments being located in different horizontal planes, one abutment being on substantially the horizontal line of the axis of the wheel when the weight of the carriage is on the wheel and the second abutment being considerably above the first abutment, and a pair of springs one for engagement by each of said abutments.

'7. In a carriage, a pair of runners, a frame structure carried by the runners, a pair of swin ing arms each pivoted at one end to one of the opposite sides of the frame, a pair of wheels one mounted near the swinging end of each or the daily the horizontal swinging arms; the swinging arms being adaptdead oenter to a position at a substantial angle above the plane of the runners, a pair ofabutments on one of said vswinging arms, :one located substantailly the same distance from the :pivot for said swinging arm as the axis 'of the wheel carried by the swinging arm, the other of said abutments being located at a greater distance from the pivotal support for said swinging arm, said :abutrnents being located in differentho ri- 'zontal planes, one abutment being on substanline of the axis of the wheel when the weight of the carriage is on the wheel and the second abutment tb'eing considerably above the first abutment, a pair of housings each having a slot into which said abutments respectively snugly fit, and a spring in one of said housings :for compression by one of said abut ments.

8. 1m a carriage, a pair of runners, a frame ing arms each pivoted at one end to one of the 8 opposite sides of the frame, a pair of wheels one mounted near the swinging end of each of the swinging arms, the swinging arms being adapted to swing from a position substantially parallel with-the base of the runners passed the lower dead center to a position at a .substantial angle above the plane of the runners, a pair of abutments on one of saidswinging arms, one located substantially the same distance from the pivot for saidswinging arm as the axis of the wheel carrier by the swingin arm, the other of said abutments being located at a greater distance from the pivotal support for said swinging arm, said abutments being located in different horizontal planes, one abutment being on substantially the horizontal line of the axis of the wheel when the weight of the carriage is on the wheel and the .second abutment being considerably above the first abutment, a pair of housings each having a slot into which said abutments respectivelyfit, and a spring in each housing for compression by said abutments. V

THOMAS F. SPACKM-AN.

Certificate of Correction Patent No. 2,403,155. July 2, 1946. THOMAS F. SPAOKMAN It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Column 8, line 11, claim 8, for the Word carrier read carried; and that the said Letters Patent should be read with this coorrection therein that the same may conform to the record of the case in the Patent fi'ice.

Signed and sealed this 1st day of October, A. D, 1946.

LESLIE FRAZER,

First Assistant C'omnnissz'aner of Patents. 

